The simplest, naive algorithm to filter out name changes would be to filter out proper names. English is relatively easy to identify proper names and there are probably established algorithms and libraries out there for it. We used something similar using a Part Of Speech tagger a few years ago, but we were using (expensive) commercial packages. https://en.wikipedia.org/wiki/Named-entity_recognition

Just identify proper names like Johnny or Suzy or Barack Obama, strip them out, and run an edit distance between what's left.